Organic light-emitting display device

ABSTRACT

An organic light-emitting display device including a plurality of pixels, each of which includes an organic light-emitting device including a pixel electrode, an organic emission layer, and an opposing electrode; a pixel defining layer covering an edge of the pixel electrode and being configured to define a light-emission region by having an opening which exposes a portion of the pixel electrode; and a reference line overlapping the pixel electrode with an insulating layer between the reference line and the pixel electrode and extending in a first direction. The reference line overlaps with a center point of the opening, and the opening is shifted to one side of the pixel electrode in a second direction perpendicular to the first direction.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. patent application Ser. No.15/801,287, filed Nov. 1, 2017, which claims priority to and the benefitof Korean Patent Application No. 10-2017-0063514, filed on May 23, 2017,each of which is hereby incorporated by reference for all purposes as iffully set forth herein.

BACKGROUND Field

Exemplary embodiments relate to an organic light-emitting displaydevice.

Discussion of the Background

Organic light-emitting display devices include two electrodes and anorganic emission layer between the two electrodes. Electrons injectedfrom a cathode, which is one of the two electrodes, and holes injectedfrom an anode, which is the other electrode, combine in the organicemission layer to form excitons. The excitons emit light while emittingenergy.

The organic light-emitting display devices include a plurality of pixelseach including an organic light-emitting device (OLED) including acathode, an anode, and an organic emission layer. Each pixel furtherincludes a plurality of transistors for driving the OLED, and acapacitor. The plurality of transistors may include a switchingtransistor and a driving transistor. Such an organic light-emittingdisplay device provides a fast response and is driven with lowconsumption power.

As resolution of organic light-emitting display devices increases,OLEDs, a plurality of transistors for driving the OLEDs, a capacitor,and lines for transmitting signals to the OLEDs, the transistors, andthe capacitor need to be arranged such that they overlap each other.However, overlapping transistors and transistors that overlap thecapacitor causes various issues such as poor brightness or a color shiftphenomenon.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the inventive concept,and, therefore, it may contain information that does not form the priorart that is already known in this country to a person of ordinary skillin the art.

SUMMARY

Exemplary embodiments provide an organic light-emitting display devicecapable of reducing a lateral side color shift and securing goodvisibility while minimizing a difference between characteristics ofpixels.

Additional aspects will be set forth in the detailed description whichfollows, and, in part, will be apparent from the disclosure, or may belearned by practice of the inventive concept.

According to exemplary embodiments, an organic light-emitting displaydevice includes a plurality of pixels, each of which includes an organiclight-emitting device including a pixel electrode, an organic emissionlayer, and an opposing electrode; a pixel defining layer covering anedge of the pixel electrode and being configured to define alight-emission region by having an opening which exposes a portion ofthe pixel electrode; and a reference line extending in a first directionand overlapping the pixel electrode with an insulating layer between thereference line and the pixel electrode. The reference line overlaps witha center point of the opening, and the opening is shifted to one side ofthe pixel electrode in a second direction perpendicular to the firstdirection.

According to exemplary embodiments, an organic light-emitting displaydevice includes a plurality of pixels, the plurality of pixels includinga plurality of first pixels, a plurality of second pixels, and aplurality of third pixels that emit different colors. Each of theplurality of first pixels includes a first organic light-emitting deviceincluding a first pixel electrode, a first organic emission layer, and afirst opposing electrode; a first pixel defining layer covering an edgeof the first pixel electrode and being configured to define alight-emission region by having a first opening which exposes a portionof the first pixel electrode; and a first reference line extending in afirst direction and overlapping the first pixel electrode with aninsulating layer between the first reference line and the first pixelelectrode. The first reference line overlaps with a center point of thefirst opening, and the first opening is shifted to one side of the firstpixel electrode in a second direction perpendicular to the firstdirection.

The foregoing general description and the following detailed descriptionare exemplary and explanatory and are intended to provide furtherexplanation of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the inventive concept, and are incorporated in andconstitute a part of this specification, illustrate exemplaryembodiments of the inventive concept, and, together with thedescription, serve to explain principles of the inventive concept.

FIG. 1 is a schematic plan view of a portion of an organiclight-emitting display device according to an exemplary embodiment.

FIG. 2 is a block diagram of an organic light-emitting display deviceaccording to an exemplary embodiment.

FIG. 3 is an equivalent circuit diagram of a pixel of an organiclight-emitting display device according to an exemplary embodiment.

FIG. 4 is a schematic layout diagram of light-emission regions of aplurality of pixels of an organic light-emitting display deviceaccording to an exemplary embodiment.

FIG. 5 is a layout diagram for schematically showing locations of aplurality of thin film transistors, a capacitor, etc. in a pixel of anorganic light-emitting display device according to an exemplaryembodiment.

FIG. 6 is a schematic layout view for explaining a relationship betweena pixel electrode of an organic light-emitting device, a light-emissionregion, and lines arranged to overlap with the light-emission region, ina pixel of an organic light-emitting display device according to anexemplary embodiment.

FIG. 7 is a cross-sectional view showing a cross-section taken alongline I-I′ of

FIG. 5 and an organic light-emitting device arranged on thecross-section.

FIG. 8 is a schematic plan view of a comparative example to be comparedwith an exemplary embodiment.

FIG. 9 is a table showing a luminance ratio for each color and colorcoordinates of white light in an embodiment of the present invention andthose in a comparative example.

FIG. 10 is a schematic layout view for explaining a relationship betweena pixel electrode of an organic light-emitting device, a light-emissionregion, and lines arranged to overlap with the light-emission region, ina pixel of an organic light-emitting display device according to anotherexemplary embodiment.

FIG. 11A and FIG. 11B are schematic layout views for explaining arelationship between a pixel electrode of an organic light-emittingdevice, a light-emission region, and lines arranged to overlap with thelight-emission region, in a pixel of an organic light-emitting displaydevice according to another exemplary embodiment.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of various exemplary embodiments. It is apparent, however,that various exemplary embodiments may be practiced without thesespecific details or with one or more equivalent arrangements. In otherinstances, well-known structures and devices are shown in block diagramform in order to avoid unnecessarily obscuring various exemplaryembodiments.

In the accompanying figures, the size and relative sizes of layers,films, panels, regions, etc., may be exaggerated for clarity anddescriptive purposes. Also, like reference numerals denote likeelements.

When an element or layer is referred to as being “on,” “connected to,”or “coupled to” another element or layer, it may be directly on,connected to, or coupled to the other element or layer or interveningelements or layers may be present. When, however, an element or layer isreferred to as being “directly on,” “directly connected to,” or“directly coupled to” another element or layer, there are no interveningelements or layers present. For the purposes of this disclosure, “atleast one of X, Y, and Z” and “at least one selected from the groupconsisting of X, Y, and Z” may be construed as X only, Y only, Z only,or any combination of two or more of X, Y, and Z, such as, for instance,XYZ, XYY, YZ, and ZZ. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.

Although the terms “first,” “second,” etc. may be used herein todescribe various elements, components, regions, layers, and/or sections,these elements, components, regions, layers, and/or sections should notbe limited by these terms. These terms are used to distinguish oneelement, component, region, layer, and/or section from another element,component, region, layer, and/or section. Thus, a first element,component, region, layer, and/or section discussed below could be termeda second element, component, region, layer, and/or section withoutdeparting from the teachings of the present disclosure.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper,” and the like, may be used herein for descriptive purposes, and,thereby, to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the drawings. Spatiallyrelative terms are intended to encompass different orientations of anapparatus in use, operation, and/or manufacture in addition to theorientation depicted in the drawings. For example, if the apparatus inthe drawings is turned over, elements described as “below” or “beneath”other elements or features would then be oriented “above” the otherelements or features. Thus, the exemplary term “below” can encompassboth an orientation of above and below. Furthermore, the apparatus maybe otherwise oriented (e.g., rotated 90 degrees or at otherorientations), and, as such, the spatially relative descriptors usedherein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms, “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. Moreover,the terms “comprises,” “comprising,” “includes,” and/or “including,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, components, and/orgroups thereof, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof.

Various exemplary embodiments are described herein with reference tosectional illustrations that are schematic illustrations of idealizedexemplary embodiments and/or intermediate structures. As such,variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, exemplary embodiments disclosed herein should not beconstrued as limited to the particular illustrated shapes of regions,but are to include deviations in shapes that result from, for instance,manufacturing. For example, an implanted region illustrated as arectangle will, typically, have rounded or curved features and/or agradient of implant concentration at its edges rather than a binarychange from implanted to non-implanted region. Likewise, a buried regionformed by implantation may result in some implantation in the regionbetween the buried region and the surface through which the implantationtakes place. Thus, the regions illustrated in the drawings are schematicin nature and their shapes are not intended to illustrate the actualshape of a region of a device and are not intended to be limiting.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure is a part. Terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and will not be interpreted in anidealized or overly formal sense, unless expressly so defined herein.

In the following examples, the x-axis, the y-axis and the z-axis are notlimited to three axes of the rectangular coordinate system, and may beinterpreted in a broader sense. For example, the x-axis, the y-axis, andthe z-axis may be perpendicular to one another, or may representdifferent directions that are not perpendicular to one another.

Although an active matrix (AM) type organic light-emitting displaydevice including seven thin film transistors (TFTs) and one capacitor inone pixel is illustrated in the accompanying drawings, embodiments ofthe present invention are not limited thereto. Accordingly, an organiclight-emitting display device according to an embodiment may include aplurality of transistors and at least one capacitor in each pixel, andmay be formed to have any of various structures in which special linesare further formed or existing lines are omitted. A pixel refers to theminimum unit in which an image is displayed, and an organiclight-emitting display device displays an image by using a plurality ofpixels.

An organic light-emitting display device according to an exemplaryembodiment will now be described in detail with reference to theaccompanying drawings.

FIG. 1 is a schematic plan view of a portion of an organiclight-emitting display device according to an exemplary embodiment. Asshown in FIG. 1, the organic light-emitting display device may include asubstrate 110, which includes a display area DA on which an image isdisplayed and a peripheral area PA around the display area DA. On thedisplay area DA of the substrate 110, a display unit that displays animage by using pixels PX each including an organic light-emitting deviceis arranged. On the peripheral area PA of the substrate 110, variouslines and/or driving units for transmitting electrical signals to thedisplay area DA may be positioned.

The display area DA includes a first pixel region R1 and a second pixelregion R2 arranged at different locations. According to the presentexemplary embodiment, respective pixels PX arranged on the first pixelregion R1 and the second pixel region R2 may have the same structures ordifferent structures. For example, arrangements between a light-emissionregion and a pixel electrode of a pixel PX, or lines thereof may differaccording to the first pixel region R1 and the second pixel region R2.

FIG. 2 is a block diagram of an organic light-emitting display deviceaccording to an exemplary embodiment.

The organic light-emitting display device may include a display unit 10including a plurality of pixels PX, a scan driving unit 20, a datadriving unit 30, a light-emission control driving unit 40, and acontroller 50.

The display unit 10 may be disposed on a display region, and may includea plurality of pixels PX at intersections of a plurality of scan linesSL1 through SLn+1, a plurality of data lines DL1 through DLm, and aplurality of light-emission control lines EL1 through ELn and arrangedin an approximate matrix. The plurality of scan lines SL1 through SLn+1and the plurality of light-emission control lines EL1 through ELn mayeach extend in a second direction, which is a row direction, and theplurality of data lines DL1 through DLm and a plurality of drivingvoltage lines ELVDDL each extend in a first direction, which is a columndirection. In a pixel line, n values of the plurality of scan lines SL1through SLn+1 may be different from those of the plurality oflight-emission control lines EL1 through ELn.

Each pixel PX may be connected to three scan lines from among theplurality of scan lines SL1 through SLn+1 connected to the display unit10. The scan driving unit 20 may generate three scan signals andtransmits the same to each pixel PX via the plurality of scan lines SL1through SLn+1. In other words, the scan driving unit 20 sequentiallyprovides scan signals to first scan lines SL2 through SLn, second scanlines SL1 through SLn−1, or third scan lines SL3 through SLn+1.

Initializing voltage lines IL may receive an initializing voltage froman external power source VINT and may provide the initializing voltageto each pixel PX.

Each pixel PX may be connected to one of the plurality of data lines DL1through DLm connected to the display unit 10 and one of the plurality oflight-emission control lines EL1 through ELn connected to the displayunit 10.

The data driving unit 30 may transmit a data signal to each pixel PX viathe plurality of data lines DL1 through DLm. Every time a scan signal isprovided to the first scan lines SL2 through SLn, the data signal may beprovided to pixels PX selected by the scan signal.

The light-emission control driving unit 40 may generate a light-emissioncontrol signal and transmits the same to each pixel PX via the pluralityof light-emission control lines EL1 through ELn. The light-emissioncontrol signal may control a light-emission time period of each pixelPX. The light-emission control driving unit 40 may be omitted accordingto internal structures of the pixels PX.

The controller 50 may change a plurality of externally-received imagesignals IR, IG, and IB to a plurality of image data signals DR, DG, andDB, and transmit the plurality of image data signals DR, DG, and DB tothe data driving unit 30. The controller 50 may receive a verticalsynchronization signal Vsync, a horizontal synchronization signal Hsync,and a clock signal MCLK, generate control signals for respectivelycontrolling the scan driving unit 20, the data driving unit 30, and thelight-emission control driving unit 40, and transmit the generatedcontrol signals to the scan driving unit 20, the data driving unit 30,and the light-emission control driving unit 40, respectively. In otherwords, the controller 50 may generate a scan driving control signal SCSfor controlling the scan driving unit 20, a data driving control signalDCS for controlling the data driving unit 30, and an emission drivingcontrol signal ECS for controlling the light-emission control drivingunit 40, and transmit the scan driving control signal SCS, the datadriving control signal DCS, and the emission driving control signal ECSto the scan driving unit 20, the data driving unit 30, and thelight-emission control driving unit 40, respectively.

Each of the plurality of pixels PX may receive a driving power supplyvoltage ELVDD and a common power supply voltage ELVSS from the outside.The driving power supply voltage ELVDD may be a predetermined high-levelvoltage, and the common power supply voltage ELVSS may be a voltagelower than the driving power supply voltage ELVDD or may be a groundvoltage. The driving power supply voltage ELVDD may be provided to eachpixel PX via a driving voltage line ELVDDL.

The plurality of pixels PX may emit light with a certain brightnessaccording to driving currents that are provided to respectivelight-emitting devices of the plurality of pixels PX, according to thedata signals received via the plurality of data lines DL1 through DLm.

FIG. 3 is an equivalent circuit diagram of a pixel PX of an organiclight-emitting display device according to an exemplary embodiment.

The pixel PX of the organic light-emitting display device according toan exemplary embodiment includes a pixel circuit PC including aplurality of thin film transistors T1 through T7 and at least onestorage capacitor Cst. The pixel PX also includes an organiclight-emitting device OLED that receives a driving current from thepixel circuit PC and emits light.

The plurality of thin film transistors T1 through T7 may include adriving thin film transistor T1, a switching thin film transistor T2, acompensating thin film transistor T3, a first initializing thin filmtransistor T4, a first light-emission control thin film transistor T5, asecond light-emission control thin film transistor T6, and a secondinitializing thin film transistor T7.

The pixel PX may include a first scan line 14 for transmitting a firstscan signal Sn to the switching thin film transistor T2 and thecompensating thin film transistor T3, a second scan line 24 fortransmitting a second scan signal Sn−1 to the first initializing thinfilm transistor T4, a third scan line 34 for transmitting a third scansignal Sn+1 to the second initializing thin film transistor T7, alight-emission control line 15 for transmitting a light-emission controlsignal En to the first light-emission control thin film transistor T5and the second light-emission control thin film transistor T6, a dataline 16 for transmitting a data signal Dm to the switching thin filmtransistor T2, a driving voltage line 26 for transmitting a drivingpower supply voltage ELVDD, and an initializing voltage line 22 fortransmitting an initializing voltage VINT for initializing the drivingthin film transistor T1.

A driving gate electrode G1 of the driving thin film transistor T1 maybe connected to a first electrode C1 of the storage capacitor Cst. Adriving source electrode S1 of the driving thin film transistor T1 maybe connected to the driving voltage line 26 via the first light-emissioncontrol thin film transistor T5. A driving drain electrode D1 of thedriving thin film transistor T1 may be electrically connected to ananode of the organic light-emitting device OLED via the secondlight-emission control thin film transistor T6. The driving thin filmtransistor T1 may receive the data signal Dm according to a switchingoperation of the switching thin film transistor T2 and supplies adriving current Id to the organic light-emitting device OLED.

A switching gate electrode G2 of the switching thin film transistor T2may be connected to the first scan line 14. A switching source electrodeS2 of the switching thin film transistor T2 may be connected to the dataline 16. A switching drain electrode D2 of the switching thin filmtransistor T2 may be connected to the driving source electrode Si of thedriving thin film transistor T1 and is also connected to the drivingvoltage line 26 via the first light-emission control thin filmtransistor T5. The switching thin film transistor T2 may be turned onaccording to the first scan signal Sn received via the first scan line14 and perform a switching operation of transmitting the data signal Dmreceived from the data line 16 to the driving source electrode Si of thedriving thin film transistor T1.

A compensating gate electrode G3 of the compensating thin filmtransistor T3 may be connected to the first scan line 14. A compensatingsource electrode S3 of the compensating thin film transistor T3 may beconnected to the driving drain electrode D1 of the driving thin filmtransistor T1 and may also be connected to the anode of the organiclight-emitting device OLED via the second light-emission control thinfilm transistor T6. A compensating drain electrode D3 of thecompensating thin film transistor T3 may be connected to the firstelectrode C1 of the storage capacitor Cst, a first initializing sourceelectrode S4 of the first initializing thin film transistor T4, and thedriving gate electrode G1 of the driving thin film transistor T1. Thecompensating thin film transistor T3 may be turned on according to thefirst scan signal Sn received via the first scan line 14 and connectsthe driving gate electrode G1 of the driving thin film transistor T1 tothe driving drain electrode D1 of the driving thin film transistor T1,such that the driving thin film transistor T1 is diode-connected.

A first initializing gate electrode G4 of the first initializing thinfilm transistor T4 may be connected to the second scan line 24. A firstinitializing drain electrode D4 of the first initializing thin filmtransistor T4 may be connected to the initializing voltage line 22. Thefirst initializing source electrode S4 of the first initializing thinfilm transistor T4 may be connected to the first electrode C1 of thestorage capacitor Cst, the compensating drain electrode D3 of thecompensating thin film transistor T3, and the driving gate electrode G1of the driving thin film transistor T1. The first initializing thin filmtransistor T4 may be turned on according to the second scan signal Sn−1received via the second scan line 24 and transmits the initializingvoltage VINT to the driving gate electrode G1 of the driving thin filmtransistor T1 to thereby initialize a voltage of the driving gateelectrode G1 of the driving thin film transistor T1.

A first light-emission control gate electrode G5 of the firstlight-emission control thin film transistor T5 may be connected to thelight-emission control line 15. A first light-emission control sourceelectrode S5 of the first light-emission control thin film transistor T5may be connected to the driving voltage line 26. A first light-emissioncontrol drain electrode D5 of the first light-emission control thin filmtransistor T5 may be connected to the driving source electrode S1 of thedriving thin film transistor T1 and the switching drain electrode D2 ofthe switching thin film transistor T2.

A second light-emission control gate electrode G6 of the secondlight-emission control thin film transistor T6 may be connected to thelight-emission control line 15. A second light-emission control sourceelectrode S6 of the second light-emission control thin film transistorT6 may be connected to the driving drain electrode D1 of the drivingthin film transistor T1 and the switching source electrode S3 of theswitching thin film transistor T3. A second light-emission control drainelectrode D6 of the second light-emission control thin film transistorT6 may be electrically connected to the anode of the organiclight-emitting device OLED. The first light-emission control thin filmtransistor T5 and the second light-emission control thin film transistorT6 may be simultaneously turned on according to the light-emissioncontrol signal En received via the light-emission control line 15, andthus the first power supply voltage ELVDD may be transmitted to theorganic light-emitting device OLED and thus the driving current Id mayflow in the organic light-emitting device OLED.

A second initializing gate electrode G7 of the second initializing thinfilm transistor T7 may be connected to the third scan line 34. A secondinitializing source electrode S7 of the second initializing thin filmtransistor T7 may be connected to the anode of the organiclight-emitting device OLED. A second initializing drain electrode D7 ofthe second initializing thin film transistor T7 may be connected to theinitializing voltage line 22. The second initializing thin filmtransistor T7 may be turned on according to the third scan signal Sn+1received via the third scan line 34 and initializes the anode of theorganic light-emitting device OLED.

A second electrode C2 of the storage capacitor Cst may be connected tothe driving voltage line 26. The first electrode C1 of the storagecapacitor Cst may be connected to the driving gate electrode G1 of thedriving thin film transistor T1, the compensating drain electrode D3 ofthe compensating thin film transistor T3, and the first initializingsource electrode S4 of the first initializing thin film transistor T4.

A cathode of the organic light-emitting device OLED may be connected tothe common power supply voltage ELVSS. The organic light-emitting deviceOLED receives the driving current Id from the driving thin filmtransistor T1 and emits light, thereby displaying an image.

According to an exemplary embodiment, a 7-transistor and 1-capacitorstructure including the second initializing thin film transistor T7 isillustrated. However, exemplary embodiments of the present invention arenot limited thereto, and the number of transistors and the number ofcapacitors may vary.

FIG. 4 is a schematic layout diagram of light-emission regions of aplurality of pixels R, G, and B of an organic light-emitting displaydevice according to an exemplary embodiment. The light-emission regionof a pixel may be defined by an opening of a pixel defining layer. Thiswill be described below.

As shown in FIG. 4, a plurality of green pixels G may be a predetermineddistance apart from each other on a first row 1N, a plurality of redpixels R and a plurality of blue pixels B alternate with each other on asecond row 2N adjacent to the first row 1N, a plurality of green pixelsG are a predetermined distance apart from each other on a third row 3Nadjacent to the second row 2N, a plurality of blue pixels B and aplurality of red pixels R alternate with each other on a fourth row 4Nadjacent to the third row 3N, and this pixel layout may be repeated upto an N-th row. In this case, the blue pixels B and the red pixels R maybe larger than the green pixels G.

The plurality of green pixels G on the first row 1N, and the pluralityof red pixels R and the plurality of blue pixels B on the second row 2Nmay zigzag. Accordingly, red pixels R and blue pixels B may alternatewith each other on a first column 1M, a plurality of green pixels G area predetermined distance apart from each other on a second column 2Madjacent to the first column 1M, blue pixels B and red pixels Ralternate with each other on a third column 3M adjacent to the secondcolumn 2M, a plurality of green pixels G are a predetermined distanceapart from each other on a fourth column 4M adjacent to the third column3M, and this pixel layout may be repeated up to an M-th column.

When describing this pixel layout differently, red pixels R may bearranged at first and third facing vertexes of the four vertexes of avirtual quadrilateral VS having a center point of a green pixel G as itscenter point, and blue pixels B are arranged at the remaining vertexes,namely, second and fourth vertexes. The virtual quadrilateral VS may bea rectangle, a rhombus, a square, or the like.

However, pixel layout structures according to exemplary embodiments arenot limited thereto. For example, a blue pixel B instead of a greenpixel G may be arranged on the center point of the virtual quadrilateralVS of FIG. 4, red pixels R may be arranged at the facing first and thirdvertexes of the four vertexes of the virtual quadrilateral VS, and greenpixels G may be arranged at the remaining vertexes, namely, the facingsecond and fourth vertexes.

This pixel layout structure of FIG. 4 may be referred to as a PenTilematrix. By applying rendering, in which a color of a pixel may beexpressed by sharing the colors of its adjacent pixels, to the PenTilematrix, high resolution may be obtained via a small number of pixels.

However, pixel layout structures according to exemplary embodiments arenot limited to the PenTile matrix. For example, exemplary embodimentsmay be applied to pixel layout structures having a strip layout, aMosaic layout, and a Delta layout. Exemplary embodiments may also beapplicable to a pixel layout structure further including a white pixelthat emits white light.

FIG. 5 is a layout diagram for schematically showing locations of aplurality of thin film transistors, a capacitor, etc. in a pixel of anorganic light-emitting display device according to an exemplaryembodiment. In FIG. 5, organic light-emitting devices OLED are omitted.FIG. 5 illustrates three pixels R, G, and B adjacent to each other.

Referring to FIG. 5, each pixel may include the driving thin filmtransistor T1, the switching thin film transistor T2, the compensatingthin film transistor T3, the first initializing thin film transistor T4,the first light-emission control thin film transistor T5, the secondlight-emission control thin film transistor T6, the second initializingthin film transistor T7, and the storage capacitor Cst.

The driving thin film transistor T1 may include a driving semiconductorlayer A1, the driving gate electrode G1, the driving source electrodeS1, and the driving drain electrode D1. The driving source electrode S1corresponds to an impurity-doped driving source region in the drivingsemiconductor layer A1, and the driving drain electrode D1 correspondsto an impurity-doped driving drain region in the driving semiconductorlayer A1. The driving gate electrode G1 may be connected to the firstelectrode C1 of the storage capacitor Cst, the compensating drainelectrode D3 of the compensating thin film transistor T3, and the firstinitializing source electrode S4 of the first initializing thin filmtransistor T4. In more detail, the driving gate electrode G1 may beintegrally formed with the first electrode C1 on the same layer. Thedriving gate electrode G1, the compensating drain electrode D3, and thefirst initializing source electrode S4 are connected to each other by afirst contact line CM1. The first contact line CM1 may be connected tothe driving gate electrode G1 via a first contact hole 51, and may beconnected to a region between the compensating drain electrode D3 andthe first initializing source electrode S4 via a second contact hole 52.

The switching thin film transistor T2 includes a switching semiconductorlayer A2, the switching gate electrode G2, the switching sourceelectrode S2, and the switching drain electrode D2. The switching sourceelectrode S2 corresponds to an impurity-doped switching source region inthe switching semiconductor layer A2, and the switching drain electrodeD2 corresponds to an impurity-doped switching drain region in theswitching semiconductor layer A2. The switching source electrode S2 maybe connected to the data line 16 via a third contact hole 53. Theswitching drain electrode D2 may be connected to the driving thin filmtransistor T1 and the first light-emission control thin film transistorT5. The switching gate electrode G2 may be formed of a portion of thefirst scan line 14.

The compensating thin film transistor T3 may include a compensatingsemiconductor layer A3, the compensating gate electrode G3, thecompensating source electrode S3, and the compensating drain electrodeD3. The compensating source electrode S3 may correspond to animpurity-doped compensating source region in the compensatingsemiconductor layer A3, and the compensating drain electrode D3corresponds to an impurity-doped compensating drain region in thecompensating semiconductor layer A3. The compensating gate electrode G3forms a dual gate electrode by a portion of the first scan line 14 and aportion of a line protruding from the first scan line 14, therebypreventing current leakage.

The first initializing thin film transistor T4 may include a firstinitializing semiconductor layer A4, the first initializing gateelectrode G4, the first initializing source electrode S4, and the firstinitializing drain electrode D4. The first initializing source electrodeS4 may correspond to an impurity-doped first initializing source regionin the first initializing semiconductor layer A4, and the firstinitializing drain electrode D4 may correspond to an impurity-dopedfirst initializing drain region in the first initializing semiconductorlayer A4. The first initializing drain electrode D4 may be connected tothe second initializing thin film transistor T7, and the firstinitializing source electrode S4 may be connected to the driving gateelectrode G1 and the first electrode C1 of the storage capacitor Cst viathe first contact line CM1 included in the second contact hole 52 andthe first contact hole 51. The first initializing gate electrode G4 maybe formed of a portion of the second scan line 24. The firstinitializing semiconductor layer A4 may form a dual gate electrode bybeing overlapped by the first initializing gate electrode G4 twice.

The first light-emission control thin film transistor T5 may include afirst light-emission control semiconductor layer A5, the firstlight-emission control gate electrode G5, the first light-emissioncontrol source electrode S5, and the first light-emission control drainelectrode D5. The first light-emission control source electrode S5 maycorrespond to an impurity-doped first light-emission control sourceregion in the first light-emission control semiconductor layer A5, andthe first light-emission control drain electrode D5 corresponds to animpurity-doped first light-emission control drain region in the firstlight-emission control semiconductor layer A5. The first light-emissioncontrol source electrode S5 may be connected to the driving voltage line26 via a fourth contact hole 54. The first light-emission control gateelectrode G5 may be formed of a portion of the light-emission controlline 15.

The second light-emission control thin film transistor T6 may include asecond light-emission control semiconductor layer A6, the secondlight-emission control gate electrode G6, the second light-emissioncontrol source electrode S6, and the second light-emission control drainelectrode D6. The second light-emission control source electrode S6 maycorrespond to an impurity-doped second light-emission control sourceregion in the second light-emission control semiconductor layer A6, andthe second light-emission control drain electrode D6 corresponds to animpurity-doped second light-emission control drain region in the secondlight-emission control semiconductor layer A6. The second light-emissioncontrol drain electrode D6 may be connected to a pixel electrode of theorganic light-emitting device OLED via a second contact line CM2connected to a fifth contact hole 55 and a via hole VIA connected to thesecond contact line CM2. The second light-emission control gateelectrode G6 may be formed of a portion of the light-emission controlline 15.

The second initializing thin film transistor T7 may include a secondinitializing semiconductor layer A7, the second initializing gateelectrode G7, the second initializing source electrode S7, and thesecond initializing drain electrode D7. The second initializing sourceelectrode S7 may correspond to an impurity-doped second initializingsource region in the second initializing semiconductor layer A7, and thesecond initializing drain electrode D7 corresponds to an impurity-dopedsecond initializing drain region in the second initializingsemiconductor layer A7. The second initializing drain electrode D7 maybe connected to a third contact line CM3 connected to a seventh contacthole 57. The third contact line CM3 may be connected to the initializingvoltage line 22 via a sixth contact hole 56. The second initializinggate electrode G7 may be formed of a portion of the second scan line 24.The second scan line 24 may serve as the third scan line 34.

The first electrode C1 of the storage capacitor Cst may be directlyconnected to the driving gate electrode G1, and may be connected to thefirst initializing thin film transistor T4 and the compensating thinfilm transistor T3 via the first contact line CM1 included in the firstcontact hole 51 and the second contact hole 52. The first electrode C1may have a floating electrode shape and overlaps the drivingsemiconductor layer A1.

The second electrode C2 of the storage capacitor Cst may overlap thefirst electrode C1 but does not overlap the entire area of the firstelectrode C1. The second electrode C2 includes an opening portion OP viawhich a portion of the first electrode C1 may be exposed, and the firstcontact hole 51 may be formed within the opening portion OP. The secondelectrode C2 may be connected to the driving voltage line 26 via aneighth contact hole 58. Respective second electrodes C2 of adjacentpixels may be formed to be connected to each other.

The first scan line 14, the second scan line 24, and the light-emissioncontrol line 15 may all be formed on the same layer and each extend inthe second direction. The first scan line 14, the second scan line 24,and the light-emission control line 15 may be formed on the same layeron which the first electrode C1 of the storage capacitor Cst may beformed.

The data line 16, the driving voltage line 26, the first contact lineCM1, the second contact line CM2, and the third contact line CM3 may allbe formed on the same layer and each extend in the first direction.

The second electrode C2 and the initializing voltage line 22 may both beformed on the same layer and each extend in the second direction.However, exemplary embodiments are not limited thereto. For example, theinitializing voltage line 22 may be formed on the same layer on whichthe first scan line 14 or the data line 16 is formed.

FIG. 6 is a schematic layout view for explaining a relationship betweena pixel electrode 310 of an organic light-emitting device OLED, aopening 150 h of a pixel defining layer 150 for defining alight-emission region, and lines arranged to overlap with the opening150 h, in a pixel of an organic light-emitting display device accordingto an exemplary embodiment. FIG. 7 is a cross-sectional view showing across-section taken along line I-I′ of FIG. 5 and the organiclight-emitting device OLED arranged on the cross-section.

Referring to FIGS. 6 and 7, the organic light-emitting display deviceaccording to an exemplary embodiment includes a plurality of pixels,each of which includes the organic light-emitting device OLED, the pixeldefining layer 150 for defining the light-emission region by using theopening 150 h, and the driving voltage line 26 corresponding to areference line.

The plurality of pixels may include a plurality of red pixels R, aplurality of green pixels G, and a plurality of blue pixels B. FIG. 6illustrates one red pixel R, one green pixel G, and one blue pixel Bfrom among the plurality of pixels. As described above, the plurality ofpixels may be arranged in a PenTile structure.

The organic light-emitting device OLED may include the pixel electrode310, an intermediate layer 320 including an organic emission layer, andan opposing electrode 330, and the light-emission region of the organiclight-emitting device OLED may be defined by the opening 150 h of thepixel defining layer 150. One of the pixel electrode 310 and theopposing electrode 330 of the organic light-emitting device OLED mayfunction as an anode, and the other may function as a cathode.

The pixel defining layer 150 may cover an edge of the pixel electrode310 and include the opening 150 h via which a portion of the pixelelectrode 310 is exposed. Because the intermediate layer 320 includingthe organic emission layer may be arranged on the portion of the pixelelectrode 310 exposed via the opening 150 h, the opposing electrode 330may be arranged on the intermediate layer 320, and light may be emittedfrom the intermediate layer 320 between the pixel electrode 310 and theopposing electrode 330. The light-emission region of the pixel may bedefined by the opening 150 h.

The driving voltage line 26, the data line 16, the first contact lineCM1, and the third contact line CM3 may be arranged under the pixelelectrode 310 with an insulating layer 140 therebetween. The lines mayall be formed on the same layer and each extend in the first direction.According to the present exemplary embodiment, the lines are arranged onan interlayer insulating layer 130.

Herein, a line overlapped by a center point CP of the opening 150 h ofthe pixel defining layer 150 and extending in the first direction, fromamong the lines may be referred to as a reference line. Given that aregion of a lower layer exposed by the opening 150 h may be a planefigure, the center point CP of the opening 150 h may mean the center ofmass of the plane figure. Alternatively, the center point may be definedas the intersection of a line forming the largest width in the firstdirection of the opening and a line forming the largest width in thesecond direction of the opening.

In FIGS. 6 and 7, the reference line may be the driving voltage line 26.However, exemplary embodiments are not limited thereto. For example,when the data line 16, the first contact line CM1, the third contactline CM3, or a line performing another function may be overlapped by thecenter point CP of the opening 150 h, the data line 16, the firstcontact line CM1, the third contact line CM3, or the line performing theother function may be a reference line.

Although respective reference lines of the red pixel R, the green pixelG, and the blue pixel B are all the driving voltage lines 26 in FIG. 6,exemplary embodiments are not limited thereto. For example, thereference lines of the red pixel R and the blue pixel B may be thedriving voltage line 26, and the reference line of the green pixel G maybe the data line 16 or the third contact line CM3.

According to the present exemplary embodiment, an additional line otherthan the reference line may be arranged on the same layer on which thereference line may be arranged, within the opening 150 h. The additionalline may be spaced apart from the reference line and may extend in thefirst direction. In this case, the number of lines arranged on one sideof the reference line may be the same as that of lines arranged on theother side of the reference line.

Within the opening 150 h of the red pixel R, the data line 16 and thefirst contact line CM1 may be arranged as additional lines on both sidesof the driving voltage line 26 being the reference line of the red pixelR, respectively. The number of lines arranged on one side of the drivingvoltage line 26 and that of lines arranged on the other side of thedriving voltage line 26 may be the same, that is, ‘1’.

Within the opening 150 h of the green pixel G, no additional lines maybe arranged on both sides of the driving voltage line 26, which is thereference line of the green pixel G. It may be considered that thenumber of lines arranged on one side of the driving voltage line 26passing the green pixel G and that of lines arranged on the other sideof the driving voltage line 26 are the same, that is, ‘0’.

Within the opening 150 h of the blue pixel B, the data line 16 and thefirst contact line CM1 may be arranged as additional lines on both sidesof the driving voltage line 26 being the reference line of the bluepixel B, respectively. The number of lines arranged on one side of thedriving voltage line 26 and that of lines arranged on the other side ofthe driving voltage line 26 may be the same, that is, ‘1’.

As such, when additional lines are arranged on both sides of thereference line, the additional lines may include a first additional linearranged on one side of the reference line and a second additional linearranged on the other side of the reference line, and a differencebetween a minimum distance between the first additional line and thereference line and that between the second additional line and thereference line may be less than 1 um. In other words, the firstadditional line and the second additional line may be arranged apartfrom each other by a symmetrical or similar distance about the referenceline.

In FIG. 6, only the driving voltage line 26 may be arranged within theopening 150 h of the green pixel G. However, exemplary embodiments arenot limited thereto. For example, by enlarging the opening 150 h of thegreen pixel G and the pixel electrode 310G, the data line 16 and thethird contact line CM3 may be arranged as additional lines within theopening 150 h. Alternatively, by shrinking the opening 150 h of the redpixel R, only the driving voltage line 26 being the reference line maybe arranged within the opening 150 h. In this way, various modificationsmay be made.

According to the present exemplary embodiment, the driving voltage line26, the data line 16, the first contact line CM1, and the third contactline CM3 corresponding to the reference line and the additional linesmay be arranged as described above in order to minimize a lateral sidecolor shift of the organic light-emitting display device and reduceasymmetrical white angular dependency (WAD).

In other words, referring to FIG. 7, when the organic light-emittingdisplay device is viewed from the front (point P) and when the organiclight-emitting display device is viewed from a side (point Q1 or Q2), acolor coordinate representing the color of a pixel may have differentvalues. When the organic light-emitting display device is viewed at aleft-side 45° angle (point Q1) and when the organic light-emittingdisplay device is viewed at a right-side 45° angle (point Q2), the colorcoordinate representing the color of a pixel may have different values.According to the present exemplary embodiment, the locations of linesarranged within the opening 150 h may be controlled to minimize avariation in the value of a color coordinate according to angles atwhich the organic light-emitting display device is recognized, and tominimize a difference between the values of color coordinates when theorganic light-emitting display device is viewed from the left side andwhen the organic light-emitting display device is viewed from the rightside.

Because the driving voltage line 26, the data line 16, the first contactline CM1, and the third contact line CM3 corresponding to the referenceline and the additional lines are arranged to overlap with the pixelelectrode 310 with the insulating layer 140 therebetween, the insulatinglayer 140 and/or the pixel electrode 310 arranged over the lines may notbe flat but may have steps due to the heights of the lines. In otherwords, due to the lines, irregularities may be vertically generated inthe insulating layer 140 and/or the pixel electrode 310 arranged overthe lines.

An influence of the steps of the lines or an influence according tolocations of the lines may change optical characteristics of pixels. Asshown in FIG. 7, steps or irregularities formed in the insulating layer140 and/or the pixel electrode 310 may affect, for example, reflectionor scattering of light and a change in the wavelength of light due toreflection of light. Accordingly, when the lines are arrangedasymmetrically, color coordinate values obtained when the organiclight-emitting display device is viewed at a left point (point Q1) andat a right point (point Q2) may have a bigger difference therebetween.

Accordingly, according to exemplary embodiments, the reference line maypass the center point CP of the opening 150 h of the pixel defininglayer 150, being the light-emission region, and the same number ofadditional lines may be arranged on the left and right sides of thereference line, whereby the light-emission region secures bilateralsymmetry.

The pixel defining layer 150 may cover the edge of the pixel electrode310 but may include the opening 150 h via which a portion of the pixelelectrode 310 may be exposed, thereby defining the light-emissionregion. The opening 150 h may be formed to be shifted to one side of thepixel electrode 310 in the second direction perpendicular to the firstdirection.

In other words, the opening 150 h may be formed such that a distance L1between respective edge points of the pixel electrode 310 and theopening 150 h that meet a virtual reference line VL, on the left side ofthe center point CP of the pixel defining layer 150, is different from adistance L2 between respective edge points of the pixel electrode 310and the opening 150 h that meet the virtual reference line VL, on theright side of the center point CP of the pixel defining layer 150. Thevirtual reference line VL may extend in the second direction whilepassing the center point CP of the opening 150 h. In FIG. 6, thedistance L2 may be greater than the distance L1. In other words, thedistance L2 between the respective edge points of the pixel electrode310 and the opening 150 h on the right side of the center point CP ofthe pixel defining layer 150 may be greater than the distance L1 betweenthe respective edge points of the pixel electrode 310 and the opening150 h on the left side of the center point CP of the pixel defininglayer 150.

According to the present exemplary embodiment, the opening 150 h of thepixel defining layer 150 may be formed to be shifted to one side of thepixel electrode 310, in order to secure uniform parasitic capacitancefor each pixel to thereby minimize a color deviation or a difference inthe other characteristics due to parasitic capacitance.

Referring to FIG. 7, the first electrode C1 and/or the second electrodeC2 of the storage capacitor Cst, and the gate electrodes G1 through G7are arranged under the pixel electrode 310. Accordingly, parasiticcapacitance may be generated between the pixel electrode 310 and thefirst electrode C1 and/or the second electrode C2 of the storagecapacitor Cst and the gate electrodes G1 through G7. If parasiticcapacitance differs between pixels, characteristics of pixels due toparasitic capacitance may be different.

According to the present exemplary embodiment, in order for each pixelto have a uniform parasitic capacitance value, the pixel electrode 310may not be shaped based on the opening 150 h of the pixel defining layer150 butshaped considering a first gate electrode or a second gateelectrode under the opening 150 h.

For example, referring to FIG. 6, the green pixel G includes a basicpixel electrode 311G and an extended pixel electrode 313G extending inthe second direction in order to secure the same parasitic capacitancevalue as that of each of the red pixel R and the blue pixel B.Accordingly, if the location of the pixel electrode 310 moves inaccordance with the location of the opening 150 h of the pixel defininglayer 150, the parasitic capacitance value may differ between pixels.Thus, the opening 150 h of the pixel defining layer 150 may be formed tobe shifted on one side of the pixel electrode 310.

A structure according to exemplary embodiments will now be described inmore detail with reference to FIG. 7. FIG. 7 illustrates an organiclight-emitting device OLED formed on the cross-section taken along lineI-I′ of FIG. 5. The line I-I′ of FIG. 5 corresponds to the line I-I′ ofFIG. 6. FIG. 7 illustrates the driving thin film transistor T1 fromamong the plurality of thin film transistors, and the storage capacitorCst.

To clarify the feature of the present invention, FIG. 7 illustrates apixel without components lowly relevant to representing the driving thinfilm transistor T1 and the storage capacitor Cst from among components,such as some lines, some electrodes, and some semiconductor layersarranged on a cross-section taken along a cutting line. Thus, thecross-section of FIG. 7 may be different from a cross-section actuallytaken along line I-I′ of FIG. 5.

Referring to FIG. 7, a substrate 110 may be formed of any of variousmaterials, for example, glass, metal, and plastic such as polyethyleneterephthalate (PET), polyethylene naphthalate (PEN), or polyimide. Thesubstrate 110 may have flexible or bendable characteristics. Thesubstrate 110 may have a structure of a single layer or multiple layersof any of the aforementioned materials.

A buffer layer 111 may be formed on the substrate 110. The buffer layer111 may increase smoothness of an upper surface of the substrate 110 orprevent or minimize infiltration of impurities from the substrate 110and the like into the driving thin film transistor T1. The buffer layer111 may include an inorganic material (such as oxide or nitride), anorganic material, or an organic and inorganic compound, and may beformed as a single layer or multiple layers of an inorganic material andan organic material. According to some exemplary embodiments, the bufferlayer 111 may have a three-layer structure of silicon oxide/siliconnitride/silicon oxide.

The driving semiconductor layer A1 of the driving thin film transistorT1 may be formed on the buffer layer 111. The driving semiconductorlayer A1 may be formed of polysilicon and may include a channel regionundoped with impurities and a source region and a drain region which aredoped with impurities and are respectively formed on both sides of thechannel region. The impurities may vary depending on the type of thinfilm transistor, and may be N-type impurities or P-type impurities.Although not shown, the switching semiconductor layer A2 of theswitching thin film transistor T2, the compensating semiconductor layerA3 of the compensating thin film transistor T3, the first initializingsemiconductor layer A4 of the first initializing thin film transistorT4, the second initializing semiconductor layer A7 of the secondinitializing thin film transistor T7, and the first light-emissioncontrol semiconductor layer A5 of the first light-emission control thinfilm transistor T5 may also be connected to the driving semiconductorlayer A1 and the second light-emission control semiconductor layer A6and may be formed simultaneously.

A first gate insulating layer GI1 may be stacked on the entire surfaceof the substrate 110 such that the first gate insulating layer GI1covers the semiconductor layers A1 through A7. The first gate insulatinglayer GI1 may be formed of an inorganic material, such as silicon oxideor silicon nitride, and have a multi-layer structure or a single-layerstructure. The first gate insulating layer GI1 insulates a semiconductorlayer from gate electrodes. According to an exemplary embodiment, thefirst gate insulating layer GI1 may be thicker than a second gateinsulating layer GI2 which may be to be described below. The first gateinsulating layer GI1 may insulate respective semiconductor layers of thedriving thin film transistor T1, the switching thin film transistor T2,the compensating thin film transistor T3, the first initializing thinfilm transistor T4, the first light-emission control thin filmtransistor T5, the second light-emission control thin film transistorT6, and the second initializing thin film transistor T7, from the gateelectrodes G1 through G7 of the thin film transistors T1 through T7,respectively. When the first gate insulating layer GI1 is thick, theparasitic capacitance between a semiconductor layer and a gate electrodemay decrease, and thus staining of an image displayed on the organiclight-emitting display device may be reduced. In the case of the drivingthin film transistor T1, the parasitic capacitance between the drivingsemiconductor layer A1 and the driving gate electrode G1 may decrease,and a gate voltage Vgs applied to the driving gate electrode G1 has awide driving range. Accordingly, light emitted from the organiclight-emitting device may be controlled to have a more extensive grayscale, by varying the magnitude of the gate voltage Vgs applied to thedriving gate electrode G1 of the driving thin film transistor T1.

The driving gate electrode G1 of the driving thin film transistor T1 andthe first electrode C1 of the storage capacitor Cst may be formed on thefirst gate insulating layer GI1.

Although not shown, the switching gate electrode G2 of the switchingthin film transistor T2, the compensating gate electrode G3 of thecompensating thin film transistor T3, the first initializing gateelectrode G4 of the first initializing thin film transistor T4, thesecond initializing gate electrode G7 of the second initializing thinfilm transistor T7, and the first light-emission control gate electrodeG5 of the first light-emission control thin film transistor T5 may besimultaneously formed with the second light-emission control gateelectrode G6, the driving gate electrode G1, and the first electrode C1.The driving gate electrode G1, the switching gate electrode G2, thecompensating gate electrode G3, the first initializing gate electrodeG4, the second initializing gate electrode G7, the first light-emissioncontrol gate electrode G5, the second light-emission control gateelectrode G6, and the first electrode C1 may be formed of a samematerial as the first gate line GL1, and are hereinafter referred to asfirst gate electrodes.

The switching gate electrode G2, the compensating gate electrode G3, thefirst initializing gate electrode G4, the second initializing gateelectrode G7, the first light-emission control gate electrode G5, andthe second light-emission control gate electrode G6 may be defined asregions where the first scan line 14, the second scan line 24, and thelight-emission control line 15 overlap with the semiconductor layer.Accordingly, a process of forming the switching gate electrode G2, thecompensating gate electrode G3, the first initializing gate electrodeG4, the second initializing gate electrode G7, the first light-emissioncontrol gate electrode G5, and the second light-emission control gateelectrode G6 may correspond to a process of forming the first scan line14, the second scan line 24, and the light-emission control line 15. Thedriving gate electrode G1 may be integrally formed with the firstelectrode C1. The first gate line GL1 may include at least one metalselected from aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag),magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir),chromium (Cr), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten(W), and copper (Cu).

According to an exemplary embodiment, the storage capacitor Cst overlapswith the driving thin film transistor T1. In detail, because the drivinggate electrode G1 and the first electrode C1 are integrally formed witheach other, the storage capacitor Cst and the driving thin filmtransistor T1 inevitably overlap each other. Because the storagecapacitor Cst may be arranged to overlap with the driving thin filmtransistor T1, the storage capacitor Cst may have a sufficient storagecapacity.

The second gate insulating layer GI2 may be stacked on the entiresurface of the substrate 110 such that the second gate insulating layerGI2 covers the first gate electrodes. The second gate insulating layerGI2 may be formed of an inorganic material, such as silicon oxide orsilicon nitride, and have a multi-layer structure or a single-layerstructure. The second gate insulating layer GI2 insulates the first gateelectrodes from second gate electrodes. The second gate insulating layerGI2 serves as a dielectric layer of the storage capacitor Cst. Toincrease the storage capacity of the storage capacitor Cst, the secondgate insulating layer GI2 may be thinner than the first gate insulatinglayer GI1.

The second electrode C2 of the storage capacitor Cst may be formed onthe second gate insulating layer GI2. The second electrode C2 may bearranged to overlap the first electrode C1. However, the secondelectrode C2 has an opening OP via which a portion of the firstelectrode C1 may be exposed. The first electrode C1 may be connected tothe compensating thin film transistor T3 and the first initializing thinfilm transistor T4 via the first contact hole 51 formed within theopening OP. The second electrode C2 may be formed of a material of thesecond gate line GL2, and may be hereinafter referred to as a secondgate electrode. Similar to the first gate line GL1, the second gate lineGL2 may include at least one metal selected from aluminum (Al), platinum(Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel(Ni), neodymium (Nd), iridium (Ir), chromium (Cr), calcium (Ca),molybdenum (Mo), titanium

(Ti), tungsten (W), and copper (Cu). The second electrode C2 of onepixel may be directly connected to the second electrode C2 of itsadjacent pixel.

An interlayer insulating layer 130 may be formed on the entire surfaceof the substrate 110 such that the interlayer insulating layer 130covers the second electrode C2 of the storage capacitor Cst. Theinterlayer insulating layer 130 may be formed of an inorganic insulatingmaterial, such as silicon oxide, silicon nitride, and/or siliconoxynitride.

An insulating layer including an inorganic material, such as the bufferlayer 111, the first gate insulating layer GI1, the second gateinsulating layer GI2, and the interlayer insulating layer 130, may beformed by chemical vapor deposition (CVD) or atomic layer deposition(ALD). This may be equally applied to exemplary embodiments to bedescribed below and modifications thereof

The driving voltage line 26, the data line 16, the first contact lineCM1, and the like are formed on the interlayer insulating layer 130, andthe insulating layer 140 may be formed on the entire surface of thesubstrate 110 to cover the data line 16, the driving voltage line 26,the first contact line CM1, and the like.

The insulating layer 140 may be formed of an organic insulatingmaterial, such as, acryl, benzocyclobutene (BCB) or hexamethyldisiloxane(HMDSO). The insulating layer 140 may be formed of an inorganicinsulating material, such as silicon oxide, silicon nitride, and/orsilicon oxynitride. The insulating layer 140 may be formed as a singlelayer or a multi-layer.

The organic light-emitting device OLED may be disposed on the insulatinglayer 140, and includes the pixel electrode 310, the opposing electrode330, and the intermediate layer 320 between the pixel electrode 310 andthe opposing electrode 330 and including an organic emission layer. Thepixel electrode 310 may be connected to the second contact line CM2 of

FIG. 5 via the via hole VIA of FIG. 5 formed in the insulating layer140. The second contact line CM2 may be connected to the secondlight-emission control drain electrode D6 and the second initializingsource electrode S7 via the sixth contact hole 56 of FIG. 5.

The pixel defining layer 150 may be disposed on the insulating layer140. The pixel defining layer 150 defines light-emission regions ofpixels by including respective openings 150 h corresponding to thepixels, namely, openings 150 h via each of which at least a portion ofthe pixel electrode 310 may be exposed. In a case as illustrated in FIG.7, the pixel defining layer 150 prevents an arc from occurring on theedge of the pixel electrode 310 by increasing a distance between theedge of the pixel electrode 310 and the opposing electrode 330 arrangedover the pixel electrode 310. The pixel defining layer 150 may be formedof an organic material, for example, polyimide or HMDSO.

The intermediate layer 320 of the organic light-emitting device OLED mayinclude a low molecular weight material or a high molecular weightmaterial. When the intermediate layer 320 includes a low-molecularweight material, the intermediate layer 320 may have a structure inwhich a hole injection layer (HIL), a hole transport layer (HTL), anorganic emission layer (EML), an electron transport layer (ETL), anelectron injection layer (EIL) are stacked in a single or complexstructure, and may include various organic materials including copperphthalocyanine (CuPc), N,N′-Di(naphthalene-1-yl)-N,N′-diphenyl-benzidine(NB), and tris-8-hydroxyquinoline aluminum (Alq3). These layers may beformed by vacuum deposition.

When the intermediate layer 320 includes a high-molecular weightmaterial, the intermediate layer 320 may generally include an HTL and anEML. In this case, the HTL may include poly(ethylenedioxythiophene)(PEDOT), and the EML may include a high-molecular weight material suchas a polyphenylene vinylene (PPV)-based material or a polyfluorene-basedmaterial. The intermediate layer 320 may be formed by screen printing,inkjet printing, laser induced thermal imaging (LITI), or the like.

The intermediate layer 320 is not limited to the structure describedabove, and may have any of various other structures. The intermediatelayer 320 may include a single layer that covers a plurality of pixelelectrodes 310 or may include patterned layers respectivelycorresponding to the plurality of pixel electrodes 310.

The opposing electrode 330 may be formed as a single body constituting aplurality of organic light-emitting devices OLED, and thus maycorrespond to the plurality of pixel electrodes 310.

When the pixel electrode 310 functions as an electrode, the pixelelectrode 310 may include a material having a high work function, suchas ITO, IZO, ZnO, or In2O3. When the organic light-emitting displaydevice is of a top-emission type, the pixel electrode 310 may furtherinclude a reflection layer including silver (Ag), magnesium (Mg),aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni),neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), ytterbium(Yb), or calcium (Ca). These materials may be independently used, or maybe combined with each other and used. The pixel electrode 310 may have asingle-layer or multi-layer structure including the aforementionedmetals and/or alloys thereof. In some exemplary embodiments, the pixelelectrode 310 may be a reflective electrode and thus may have anITO/Ag/ITO structure.

When the opposing electrode 330 functions as a cathode electrode, theopposing electrode 330 may be formed of a metal, such as silver (Ag),magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au),nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li),or calcium (Ca). When the organic light-emitting display device is of atop-emission type, the opposing electrode 330 needs to be able totransmit light. According to some exemplary embodiments, the opposingelectrode 330 may include transparent conductive metal oxide, such asITO, IZO, ZnO, or In2O3.

According to another exemplary embodiment, the opposing electrode 330may include a thin film including at least one of Li, Ca, LiF/Ca,LiF/Al, Al, Ag, Mg, or Yb. For example, the opposing electrode 330 mayhave a single-layer or stacked-layer structure of Mg:Ag, Ag:Yb, and/orAg.

As shown in FIGS. 6 and 7, various lines under the pixel electrode 310overlap each other, and thus the insulating layer 140 and/or the pixelelectrode 310 arranged over the various lines may form a step and not beflat. In other words, due to the lines, irregularities may be verticallygenerated on the insulating layer 140 and/or the pixel electrode 310arranged over the lines.

According to exemplary embodiments, in order to minimize an influence ofthe steps of the lines or an influence according to locations of thelines, the reference line passes the center point CP of the opening 150h of the pixel defining layer 150, being the light-emission region, andadditional lines are arranged on left and right sides of the referenceline, whereby the light-emission region secures bilateral symmetry.

According to exemplary embodiments, the opening 150 h of the pixeldefining layer 150 may be shifted to one side of the pixel electrode 310to form an inequality of 11<12, so that a parasitic capacitance that maybe generated between the pixel electrode 310 and the first and/or secondgate electrodes may be secured uniformly for pixels.

FIG. 8 is a schematic plan view of a comparative example to be comparedwith an exemplary embodiment.

Referring to FIG. 8, first contact lines CM1, which are reference lines,pass center points CP of holes of a red pixel R′ and a blue pixel B′,but the number of additional lines arranged on one side of each firstcontact line CM1, which may be the reference line, may be not the sameas that of additional lines arranged on the other side of each firstcontact line CM1.

In the case of the red pixel R′, one additional line, namely, thedriving voltage line 26, may be arranged on the left side of the firstcontact line CM1 being the reference line, and no additional lines arearranged on the right side of first contact line CM1 being the referenceline.

In the case of the blue pixel B′, one additional line, namely, thedriving voltage line 26, may be arranged on the left side of the firstcontact line CM1 being the reference line, and no additional lines maybe arranged on the right side of the first contact line CM1 being thereference line.

In the case of the green pixel G′, no reference lines may be arranged onthe center point CP of the hole.

The opening 150 h′ of each of the pixels R′, G′, and B′ may be notshifted to one side of the pixel electrode 310 in the second direction.In other words, a distance L1′ between respective edge points of thepixel electrode 310 and the opening 150 h′ that meet a virtual referenceline VL, on the left side of the center point CP of the pixel defininglayer 150, may be substantially the same as a distance L2′ betweenrespective edge points of the pixel electrode 310 and the opening 150 h′that meet the virtual reference line VL, on the right side of the centerpoint CP of the pixel defining layer 150. The virtual reference line VLextends in the second direction while passing the center point CP of theopening 150 h′. In other words, it may be illustrated that the distanceL2′ between the respective edge points of the pixel electrode 310 andthe opening 150 h′ on the right side of the center point CP of the pixeldefining layer 150 may be equal to the distance L1′ between therespective edge points of the pixel electrode 310 and the opening 150 h′on the left side of the center point CP of the pixel defining layer 150(L1′=L2′).

FIG. 9 is a table showing a luminance ratio for each color and colorcoordinates of white light in an exemplary embodiment and those in acomparative example.

In FIGS. 9, R_45°, G_45°, and B_45° respectively indicate luminanceratios of red, green, and blue colors measured on a 45° lateral siderelative to the front side. In other words, given that brightnessmeasured on the front side may be 100%, R_45°, G_45°, and B_45° refer toluminance ratios for red, green, and blue colors, respectively.According to an exemplary embodiment, the luminance ratios for red,green, and blue colors measured on the 45° lateral side are respectively44.9%, 41.2%, and 37.5%, which are all greater than those according tothe comparative example.

In FIG. 9, W_x and W_x′ indicate x values of a CIE 1931 color coordinatesystem. W_x refers to an x coordinate of white light measured on thefront side, and W_x′ refers to an x coordinate of white light measuredon a 45° lateral side. Being that a change in an x coordinate meanshaving an influence on a red color. Δx refers to a change between colorcoordinate values on the front side and on the lateral side, which isW_x′-Wx.

In the comparative example, the x value of the color coordinate differsbetween the front side and the lateral side. However, according to anexemplary embodiment, the value of the color coordinate did not change.In other words, according to an exemplary embodiment, brightness on thelateral side of each pixel may be improved, and a color shift phenomenonmay be reduced.

FIG. 10 is a schematic layout view for explaining a relationship betweenthe pixel electrode 310 of the organic light-emitting device OLED, theopening 150 h of the pixel defining layer 150 for defining alight-emission region, and the lines arranged to overlap with theopening 150 h, in a pixel of an organic light-emitting display deviceaccording to another exemplary embodiment.

Referring to FIG. 10, the organic light-emitting display deviceaccording to another exemplary embodiment includes a plurality ofpixels, each of which includes the organic light-emitting device OLED,the pixel defining layer 150 for defining the light-emission region byusing the opening 150 h, and the driving voltage line 26 correspondingto a reference line. The plurality of pixels may include a plurality ofred pixels R, a plurality of green pixels G, and a plurality of bluepixels B.

In the organic light-emitting display device according to anotherexemplary embodiment, only some of the red pixel R, the green pixel G,and the blue pixel B include reference lines arranged to overlap withthe center point CP of the opening 150 h, and the number of additionallines arranged on one side of each reference line may be the same asthat of additional lines arranged on the other side of the referenceline. The additional lines mean lines arranged to overlap with theopening 150 h.

Referring to FIG. 10, in the case of the green pixel G and the bluepixel B, a reference line may be arranged to overlap with the centerpoint CP of the opening 150 h, and the number of additional linesarranged on one side of the reference line may be the same as that ofadditional lines arranged on the other side of the reference line.

In other words, it may be considered that the number of lines arrangedon one side of the driving voltage line 26 passing the green pixel G andthat of lines arranged on the other side of the driving voltage line 26are the same, that is, ‘0’.

Within the opening 150 h of the blue pixel B, the data line 16 and thefirst contact line CM1 are arranged as additional lines on both sides ofthe driving voltage line 26 being the reference line of the blue pixelB, respectively. The number of lines arranged on one side of the drivingvoltage line 26 and that of lines arranged on the other side of thedriving voltage line 26 are the same, that is, ‘1’.

As such, when additional lines are arranged on both sides of thereference line, the additional lines may include a first additional linearranged on one side of the reference line and a second additional linearranged on the other side of the reference line, and a differencebetween a minimum distance between the first additional line and thereference line and that between the second additional line and thereference line may be less than 1 um . In other words, the firstadditional line and the second additional line may be arranged apartfrom each other by a symmetrical or similar distance about the referenceline.

In the case of the red pixel R, one additional line, namely, the drivingvoltage line 26, may be arranged on the left side of the first contactline CM1 being the reference line, and no additional lines may bearranged on the right side of the first contact line CM1 being thereference line.

The opening 150 h of each of the green and blue pixels G and B may beformed to be shifted to one side of the pixel electrode 310 in thesecond direction perpendicular to the first direction. On the otherhand, the opening 150 h of the red pixel R may not be shifted to oneside of the pixel electrode 310 in the second direction.

In other words, in the case of the green pixel G and the blue pixel B,the opening 150 h may be formed such that a distance L1 betweenrespective edge points of the pixel electrode 310 and the opening 150 hthat meet a virtual reference line VL, on the left side of the centerpoint CP of the opening 150 h, is different from a distance L2 betweenrespective edge points of the pixel electrode 310 and the opening 150 hthat meet the virtual reference line VL, on the right side of the centerpoint CP of the opening 150 h. The virtual reference line VL may extendin the second direction while passing the center point CP of the opening150 h. In FIG. 10, the distance L2 may be greater than the distance L1.In other words, the distance L2 between the respective edge points ofthe pixel electrode 310 and the opening 150 h on the right side of thecenter point CP of the opening 150 h may be greater than the distance L1between the respective edge points of the pixel electrode 310 and theopening 150 h on the left side of the center point CP of the opening 150h.

In the case of the red pixel R, the opening 150 h may be formed suchthat a distance L1 between respective edge points of the pixel electrode310 and the opening 150 h that meet a virtual reference line VL, on theleft side of the center point CP of the opening 150 h, may besubstantially the same as a distance L2 between respective edge pointsof the pixel electrode 310 and the opening 150 h that meet the virtualreference line VL, on the right side of the center point CP of theopening 150 h. The virtual reference line VL may extend in the seconddirection while passing the center point CP of the pixel defining layer150.

According to the present exemplary embodiment, the red pixel R has thesame structure as the red pixel R′ in the comparative example of FIG. 8,and the green pixel G and the blue pixel B have the same structures asthose according to the exemplary embodiment of FIG. 6. This may be astructure for minimizing a difference between luminance ratios of red,green, and blue pixels on the 45° lateral side relative to the frontside, based on the data of FIG. 9.

FIGS. 11A and 11B are schematic layout views of some pixels included inthe first pixel region R1 of FIG. 1 and some pixels included in thesecond pixel region R2 of FIG. 1 in an organic light-emitting displaydevice according to another exemplary embodiment, wherein the first andsecond pixel regions R1 and R2 are arranged at different locations.

Referring to FIGS. 11A and 11B, in the case of green pixels Gin thefirst pixel region R1 and the second pixel region R2, a reference linemay be arranged within the opening 150 h to overlap with the centerpoint CP of the opening 150 h, and the number of lines arranged on oneside of the reference line may be the same as that of lines arranged onthe other side of the reference line. In the first pixel region R1 andthe second pixel region R2, the opening 150 h of each of the greenpixels G may be formed to be shifted to one side of the pixel electrode310 in the second direction perpendicular to the first direction. Such astructure of the green pixel G may be reflected in not only the firstpixel region R1 and the second pixel region R2 but also the entiredisplay region of the organic light-emitting display device.

However, a red pixel R and a blue pixel B in the first pixel region R1may have different structures from those in the second pixel region R2.According to some exemplary embodiments, the first pixel region R1 andthe second pixel region R2 may be aligned on a straight line extendingin the second direction, the first pixel region R1 may be on the leftside of the display region of the organic light-emitting display device,and the second pixel region R2 may be on the right side of the displayregion of the organic light-emitting display device.

In the first pixel region R1, the opening 150 h of the red pixel R maybe shifted to the left side of a pixel electrode 310R. In the firstpixel region R1, the opening 150 h of the blue pixel B may be shifted tothe left side of a pixel electrode 310B. (L1<L2).

In the second pixel region R2, the opening 150 h of the red pixel R maybe shifted to the right side of the pixel electrode 310R. In the secondpixel region R2, the opening 150 h of the blue pixel B may be shifted tothe right side of a pixel electrode 310B. (L1>L2).

According to the present exemplary embodiment, the degree to which theopening 150 h of the red pixel R and the opening 150 h of the blue pixelB are shifted to the left or right side of the pixel electrode 310 mayvary according to locations of the display region. For example, in adirection from the left side of a pixel region toward the right sidethereof in the second direction, the value of the distance L1 maygradually increase.

However, exemplary embodiments are not limited thereto. For example, theopening 150 h of the red pixel R in the first pixel region R1 may beshifted to the right side of the pixel electrode 310R, and the opening150 h of the red pixel R in the second pixel region R2 may be shifted tothe left side of the pixel electrode 310R. In this way, variousmodifications may be made.

According to the present exemplary embodiment, in the case of the greenpixels G, a line layout within the opening 150 h may maintain uniformityregardless of locations of the pixel region, and, in the case of the redpixels R and the blue pixels B, a line layout within the opening 150 hmay be controlled according to locations of the pixel region. Due tothis control, a difference between right-side WAD and left-side WAD ofthe organic light-emitting display device may be minimized.

According to various exemplary embodiments, uniform characteristicsbetween pixels may be maintained, and also a lateral side color shift ofan organic light-emitting display device may be minimized and uniformitybetween right-side WAD and left-side WAD of the organic light-emittingdisplay device may be obtained.

Of course, the scope of the present invention may be not limitedthereto.

Although certain exemplary embodiments and implementations have beendescribed herein, other embodiments and modifications will be apparentfrom this description. Accordingly, the inventive concept is not limitedto such embodiments, but rather to the broader scope of the presentedclaims and various obvious modifications and equivalent arrangements.

What is claimed is:
 1. An organic light-emitting display devicecomprising: a plurality of pixels, at least one of the plurality ofpixels comprising an organic light-emitting device comprising a pixelelectrode, an organic emission layer, and an opposing electrode; a pixeldefining layer covering the pixel electrode defining a light-emissionregion by having an opening which exposes a portion of the pixelelectrode; and a via hole overlapping the pixel electrode, wherein: afirst distance between a first boundary of the pixel electrode and afirst virtual line (VL) is different from a second distance between asecond boundary of the pixel electrode and the first VL; the first VLextends in a first direction and passes through a center point of theopening; the first boundary and the second boundary are arranged onopposite sides of the first virtual line; the plurality of pixelscomprise a red pixel, a green pixel, and a blue pixel; the via hole ofthe red pixel, the via hole of the green pixel, and the via hole of theblue pixel are arranged on a second VL, the second VL extends in asecond direction perpendicular to the first direction in a plan view. 2.The organic light-emitting display device of claim 1, wherein: each ofthe plurality of pixels further comprises a driving thin film transistorarranged on a substrate and comprising a driving gate electrode; and atleast a portion of the pixel electrode overlaps with the driving gateelectrode.
 3. The organic light-emitting display device of claim 2,wherein: each of the plurality of pixels further comprises a storagecapacitor overlapping with the driving thin film transistor andcomprising a first electrode and a second electrode; and the firstelectrode is integrally formed with the driving gate electrode.
 4. Theorganic light-emitting display device of claim 3, wherein: the drivingthin film transistor comprises a driving semiconductor layer arrangedunder the driving gate electrode and insulated from the driving gateelectrode by a first gate insulating layer; and a second gate insulatinglayer is arranged between the first electrode and the second electrode.5. The organic light-emitting display device of claim 1, furthercomprising a reference line extending in a first direction andoverlapping the pixel electrode with an insulating layer disposedbetween the reference line and the pixel electrode, wherein thereference line overlaps with a center point of the opening.
 6. Theorganic light-emitting display device of claim 5, wherein the referenceline is a driving voltage line configured to transmit a driving voltageto each pixel.
 7. The organic light-emitting display device of claim 1,wherein the plurality of pixels are arranged in a pentile matrix pixelarray.
 8. An organic light-emitting display device comprising: aplurality of pixels, at least one of the plurality of pixels comprisingan organic light-emitting device comprising a pixel electrode, anorganic emission layer, and an opposing electrode; a pixel defininglayer covering the pixel electrode and being configured to define alight-emission region by having an opening which exposes a portion ofthe pixel electrode; and a via hole overlapping the pixel electrode,wherein: the pixel electrode includes a 1st region, a 2nd region, a 3rdregion, and a 4th region divided by a first virtual line (VL) and ahorizontal VL; the first VL extends in a first direction and passesthrough a center point of the opening; the horizontal VL perpendicularto the first VL and passes through the center point of the opening; thevia hole is disposed in the 1st region; and is at least one of the 2ndregion, the 3rd region, and the 4th region has a different size.
 9. Theorganic light-emitting display device of claim 8, wherein: thehorizontal VL is disposed between the 2nd region and 3rd region; and the2nd region and 3rd region are symmetric with respect to the horizontalVL.
 10. The organic light-emitting display device of claim 8, wherein:the first VL is disposed between the 1st region and 4th region; thehorizontal VL is disposed between the 2nd region and 3rd region; and asize of the 2nd region is different from a size of the 4th region.